The N-Tester Clip is a design collaboration that we were working on with the Norwegian crop nutrition company Yara International. It is an optical clip to determine nitrogen demands of different crops through chlorophyll measurements by using a standard smartphone in combination with the Yarairix App. The idea behind this product innovation in the field of digital farming is developed by Yara and the first of its kind. The N-Tester Clip enables farmers around the planet to simply use their smartphones for precision farming.